Replace water pump on 2002 Chevy Suburban?

Answer 1

Just did this.

Take off the fan shroud first so you can see what you are working on.

Drain the coolant from the radiator. (pull down small hose on drivers side of radiator and open valve at bottom of radiator next to hose entry). You should also find the engine block drains and drain from there. (I couldn't find mine - you'll see the problem later).

Remove the serpentine belt. (put a wrench on the idler pulley nut at the top left of the belt's path, and pull inwards, the belt will loosen).

Loosen the fan clutch nut that connects the fan to the water pump flywheel. It's the big nut behind the fan. You'll have to use a big wrench and something to hold the water pump wheel. I used a regular pipe wrench and an old belt wrapped around the wheel to hold it. It will pop when it breaks loose so give it some good pumps instead of trying to slow turn it.

Take off the fan and fan clutch assembly. No need to remove the fan from the clutch.

Remove the idler wheel assembly from the top left of the water pump assembly while it's still on the engine - you'll have more leverage.

Now you'll see why you want to drain the engine block from the plugs of all remaining antifreeze. Put a large pan - like a cement mixing tray - under the car. Loosen and slide back the pipe clamps on all of the hoses going into the water pump. Should be three pipes going in - two small, one large. There will be coolant leaking onto the floor if you did not put the pan under the water pump assembly.

Loosen and remove the bolts holding on the thermostat assembly. You don't have to remove the thermostat from its housing, but you may want to replace it now.

Loosen the six bolts on the water pump assembly and pull it off the engine block. You will have more coolant leaking on the floor here as well. Use mineral spirits and a PLASTIC scraper to remove any residue from the old gaskets on the block.

Make sure your new pump matches the old pump. There may be some variations in the appearance of the gaskets but the openings should look the same and be in the same places. If you have a fiber gasket kit, use a light coating of RTV sealant on the flat gaskets - both sides - to seal the gasket. Use a small amount of silicone grease on the "O" ring that connects to the thermostat assembly.

Insert two of the water pump bolts into the new assembly. Carefully place the new water pump housing onto the engine block, using the two bolts to line up the entire unit. Hand tighten all six bolts while holding the unit onto the block. Now carefully tighten each bolt using a star pattern sequence until all are at the correct torque. I did not have a torque wrench that fit this size bolt, so I had to go by "feel"- I'll let you know in 10,000 miles if it worked.

Re attach the thermostat housing and all the hoses. Shut off the radiator drain valve and replace the small hose to its old position. Double check all hoses and bolts. Attach the Idler pulley, re-install the serpentine belt and replace the fan shrouds.

To refill the coolant system, use the proper coolant (see manual) and fill at the expansion tank. You should be able to put two gallons in before it appears full. Now start the engine with the heater controls (front and back) on high heat and full fan. Run for about 1 minute and shut off. You should have an empty expansion tank. Fill it up again, as much as you can without overflowing. Turn car on again. In total, the engine holds four gallons of coolant. If you did not drain all of it out, you will obviously be replacing less than 4 gallons.

Good luck.